Epidemiology of Benign Prostate Disease

All intact men will have prostatic enlargement as they grow older; of these a high proportion will develop symptoms of bladder outflow obstruction and this proportion increases with advancing age so that 30% of men in their seventies may have objective symptoms severe enough to warrant investigation and treatment. It is almost impossible to obtain post mortem tissue from elderly men in the UK without histological evidence of benign prostatic hyperplasia.

There are enormous differences world-wide in the incidence of benign prostatic enlargement and prostate cancer; in general developed countries with a diet rich in animal fats have the highest incidence. Racial differences are striking, with black men having a higher incidence than whites who in turn have a higher incidence than Asians. This relationship is paralleled in the normal serum testosterone levels in the three groups.

In underdeveloped countries shorter male life expectancy (thus reducing the at risk cohort relative to the population) and under-reporting may bias the figures, but migrant studies do tend to confirm the epidemiological suggestions that this is a disease of western lifestyles. Possibly the most attractive hypothesis is that the pathogenesis is mediated by metabolism of ingested fats to produce excess amounts of circulating sex hormone homologues which may derange the normal interaction between the prostate stromal cells and their epithelial neighbours. In experimental systems this can be seen where oestrogens are co-administered with testosterone. Moreover prostatic enlargement does not occur in eunuchs who are castrated before puberty but does occur in male to female transsexuals!

This situation is largely mirrored in prostate cancer

The British man with symptoms of benign prostatic disease appears rather more stoical than his North American or Western European cousins. It is obvious that with only one consultant urologist for every 120,000 people in the UK, there is no way that every elderly man with symptoms of bladder outflow obstruction can be managed exclusively in a hospital based system. Thus with the combination of an increasingly aged population and heightened awareness of men’s’ health issues it is vital that the majority of these patients should be looked after in a primary care

Stress may play a role in the development of prostatic pain, as may a past history of sexually transmitted disease, but this remains unclear.